Atom transfer radical polymerization (ATRP): A versatile and forceful tool for functional membranes

The progress in atom transfer radical polymerization (ATRP) provides an effective means for the design and preparation of functional membranes. Polymeric membranes with different macromolecular architectures applied in fuel cells, including block and graft copolymers are conveniently prepared via ATRP. Moreover, ATRP has also been widely used to introduce functionality onto the membrane surface to enhance its use in specific applications, such as antifouling, stimuli-responsive, adsorption function and pervaporation. In this review, the recent design and synthesis of advanced functional membranes via the ATRP technique are discussed in detail and their especial advantages are highlighted by selected examples extract the principles for preparation or modification of membranes using the ATRP methodology.     

微反应器中乙炔法合成N-乙烯基吡咯烷酮的过程研究

搭建了以商用微反应器为核心的气液微反应系统,成功实现了加压乙炔法合成N-乙烯基吡咯烷酮（NVP）的产品过程,采用液相循环方式完成反应物2-吡咯烷酮的高效转化,全面考察了反应温度、KOH含量、内构件数量和原料乙炔纯化对液相反应的影响。结果表明,反应温度和KOH含量对选择性有显著影响,高温和高含量催化剂会严重降低产物NVP的选择性,综合调控反应温度和KOH含量,可保证产物选择性在95%以上;微反应器中内构件的存在有利于促进气液传质过程;反应体系水分的脱除有助于循环反应中转化率和选择性的提高;与高压釜相比,产物NVP收率提高了28.7%（无助剂）,反应时间有适当缩短。     

抗高温降失水剂AMPS／AM／NVP共聚物的合成及性能

以2-丙烯酰胺基-2-甲基丙磺酸（AMPS）、丙烯酰胺（AM）和N-乙烯基吡咯烷酮（NVP）为原料，采用水溶液自由基共聚法合成了抗高温、抗盐油井水泥降失水剂AMPS／AM／NVP三元共聚物，确定了聚合物降失水剂的最佳合成条件。该降失水剂能将淡水水泥浆的API失水量控制在50mL以内，饱和盐水水泥浆API失水量控制在100mL以内。以该降失水剂为主剂的水泥浆体系在150℃以内都具有较低的失水量，形成的水泥浆及水泥石综合性能良好。     

耐温耐盐酚醛冻胶研制及性能调控机理

注水油藏控水稳油过程中最常用的堵剂之一是聚合物冻胶,而存在高温高盐苛刻条件的油藏中冻胶应用的关键是其耐温抗盐性能。因此分别评价了在盐含量为25×10⁴mg/L的模拟盐水中,110℃和155℃条件下不同分子结构的丙烯酰胺(AM)/2-丙烯酰胺-2-甲基丙磺酸(AMPS)二元共聚物和AM/AMPS/N-乙烯基吡咯烷酮(NVP)三元共聚物与对苯二酚、六亚甲基四胺交联制备的冻胶成胶性能,明确了以AMPS含量为30%的AM/AMPS共聚物做主剂更容易形成稳定冻胶。通过分析不同脱水程度冻胶的固体核磁共振碳谱(C-NMR)谱图发现,耐温耐盐冻胶的重要特征是长期热处理后仍保持一定含量的酰胺基甲基丙磺酸。在此基础上综合冻胶的冷冻扫描电镜(Cryo-SEM)和红外光谱(FTIR)分析结果认为,选择高AMPS含量的聚合物,调控交联剂的用量,可以优化冻胶中伯酰胺、酰胺基甲基丙磺酸等盐敏基团的存在状态,由此有效抑制酰胺基甲基丙磺酸的内催化水解,从而调控冻胶的耐温耐盐性能。     

Synthesis of alkyne‐terminated xanthate RAFT agents and their uses for the controlled radical polymerization of N‐vinylpyrrolidone and the synthesis of its block copolymer using click chemistry

Two new alkyne‐terminated xanthate reversible addition‐fragmentation chain‐transfer (RAFT) agents: (S)‐2‐(Propynyl propionate)‐(O‐ethyl xanthate) (X₃) and (S)‐2‐(Propynyl isobutyrate)‐(O‐ethyl xanthate) (X₄) were synthesized and characterized and used for the controlled radical polymerization of N‐vinylpyrrolidone (NVP). X₃ showed better chain transfer ability in the polymerization at 60°C. Molecular weight of the resulted polymer increased linearly with the increase in monomer loading. Kinetics study with X₃ showed the pseudo‐first order kinetics up to 67% monomer conversion. Molecular weight (M_n) of the resulting polymer increased linearly with the increase in the monomer conversion up to around 67%. With the increase in the monomer conversion, polydispersity of the corresponding poly(NVP)s initially decreased from 1.34 to 1.32 and then increased gradually to 1.58. Chain‐end analysis of the resulting polymer by ¹H‐NMR and FTIR showed clearly that polymerization started with radical forming out of xanthate RAFT agent. Living nature of the polymerization was also confirmed from the successful homo‐chain extension experiment and the hetero‐chain extension experiment involving synthesis of poly(NVP)‐b‐polystyrene amphiphilic diblock copolymer. Formed alkyne‐terminated poly(NVP) also allowed easy conjugation to azide‐terminated polystyrene by click chemistry to prepare well‐defined poly(NVP)‐b‐polystyrene block copolymers. Resulting polymers were characterized by GPC, ¹H‐NMR, FTIR, and thermal study. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

DMAEMA/NVP/HEMA共聚物水凝胶的合成与性能研究

以甲基丙烯酸N,N-二甲氨基乙酯(DMAEMA)、N-乙烯基吡咯烷酮(NVP)和甲基丙烯酸β-羟乙酯(HEMA)为共聚单体,采用自由基水溶液聚合法制备了化学交联的三元共聚水凝胶,并对水凝胶在不同温度和不同离子强度及不同pH介质中的溶胀性能进行了测定。结果表明,在不同离子强度(I)的水溶液中,随着I的增大,水凝胶的平衡溶胀比ESR不断降低;但当I>0.2后,对凝胶ESR的影响不显著;当外界环境酸度较大(pH<2)时,凝胶ESR较大,但pH值稍有增大,凝胶ESR迅速下降;温度升高,凝胶ESR减少。     

互穿网络水凝胶角膜接触镜材料的合成及性能

通过高聚物分子设计的方法,运用互穿网络(IPN)技术,以吸水倍率为1.7的甲基丙烯酸β-羟乙酯(HEMA)水凝胶为基体材料,以吸水倍率为7~8的交联N-乙烯基吡咯烷酮(PVPP)颗粒为分散相,制备出了互穿程度不同的复合水凝胶角膜接触镜材料。利用SEM和TG分析仪对合成物的结构及热稳定性进行了表征。结果表明,m(PVPP颗粒)∶m(单体HEMA)=10∶90,以w(甘油或PEG400)=35%~45%作致孔剂,通过控制液体HEMA在PVPP颗粒中的渗透程度,可制得膨润率2%~5.3%、拉伸强度430~695 kPa、透光率>92%、含水质量分数45%左右的中等含水量的复合水凝胶角膜接触镜材料。DTG分析发现,在20~40℃,复合水凝胶的脱水速率随着互穿网络程度的提高而降低。     

共聚物水凝胶的合成及其溶胀性能研究

以过氧化二苯甲酰(BPO)为引发剂，合成了N-乙烯基吡咯烷酮(NVP)-甲基丙烯酸肛羟乙酯(HEMA)-甲基丙烯酸丁酯(BMA)共聚物水凝胶，可作为软性角膜接触镜材料。探讨了不同比例的NVP、HEMA、BMA对材料溶胀性能的影响。     

低温等离子体液相接枝NVP改性PAN膜

采用液相等离子体接枝技术改性聚丙烯腈(PAN)膜,在PAN膜表面引入亲水性单体氮乙烯吡咯烷酮(NVP).通过傅立叶红外光谱、DSC、XPS对PAN改性膜进行了表征,研究了单体浓度、温度、接枝时间对PAN改性膜纯水通量的影响,考察了在不同单体接枝温度下,PAN改性膜对NaCl、MgSO4混合盐体系的分离性能.